This invention relates to gas-cleaning equipment and its use. More particularly, it relates to gas-cleaning equipment for cleaning pollutant-contaminated gases discharged from factories and automobiles and to its use.
With the development of industrial technology, harmful pollutants contained in exhaust gases discharged from various factories have injured the health of the residents, have induced diseases of respiratory system such as asthma, and have caused atmospheric pollution, as is well known. In recent years, with the development of, particularly, the automobile industry, pollutant gases such as CO.sub.x, NO.sub.x, SO.sub.x, etc. exhausted from automobiles, particularly, diesel engine automobiles have injured the health of residents along the roads and have caused atmospheric pollution. This has become a serious problem throughout the world, and measures against it have been urged.
As the measures, there have been proposed various exhaust gas-cleaning equipment including large-scale ones for exhaust gases discharged from factories and comparatively compact ones required for automobiles. In these conventional gas-cleaning equipment, it has been necessary to combine a plurality of comparatively large-sized equipment or use a large amount of a catalyst for the purpose of enhancing the ability of cleaning pollutants-contaminated gases, which in turn causes the problems that the cleaning equipment becomes too large and too expensive. Thus, there have been various proposals which are directed to reduce the size or cost of the equipment. One effective example thereof is a gas-cleaning equipment utilizing plasma discharge.
However, such proposals are still insufficient as to the level of the cleaning ability. The Administration cannot permit the present very slow progress of the measures against pollutant gases, and requires more advanced measures.
Under such circumstances, there has recently been proposed an effective gas-cleaning equipment in which a gas-cleaning technique utilizing a catalyst is combined with a gas-cleaning technique of utilizing plasma discharge ("Shingaku Gihou", 1993-01, Denshi Joho Tsushin Gakkai).
According to this report, a catalyst-plasma-reactor element using a reed switch is used for decomposing the pollutant gases such as NO.sub.x, SO.sub.x and CO.sub.x to thereby effectively combine the catalytic action of Rh contact point metals with the gas-decomposing action of plasma generated by glow discharge for effectively attaining cleaning of pollutant-contaminated gases.
However, this report discloses only a fundamental theory of a system which can effectively clean pollutant-contaminated gases but does not disclose a specific structure of equipment realizing the theory.